The present invention relates to a method of and a system for a shift control in an automatic transmission drivingly coupled with an engine with a load control member.
U.S. Pat. No. 4,730,521 issued to Hayasaki et al. on Mar. 15, 1988 and European Patent Application published under publication No. 0214467 on Oct. 19, 1988 disclose an automatic transmission including a forward one-way clutch and a low one-way clutch. In the known automatic transmission, the one-way clutch overruns to effect a smooth shockless shift. The provision of the one-way clutches has made contribution to simplification of an engagement control of an on-coming or an apply friction element. However, the provision of such one-way clutches are obstacles to making the automatic transmissions compact. In order to remove the one-way clutches, SAE papers 890529 and 905048 propose an adaptive control for clutch-to-clutch shifting.
An object of the present invention is to provide an improved method of and system for a shift control in an automatic transmission such that a shift quality is improved considerably by preventing occurrence of engine racing while providing increased freedom in selecting initiation timing of engagement of an on-going or apply friction element.